Photographic copying paper



Patented July 13,1943

UNITED STATES PATENT OFFICE 2,324,060 PHOTOGRAPHIC COPYING PAPER Fred W. Boughton, Rochester, N. Y., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. Application October 9, 1940,

Serial No. 360,444

15 Claims. (Cl. 95-6) salt sensitizer selected from the group consisting of ferric chloride, mercuric chloride, mereuric acetate, stannic chloride, zinc chloride, and. cupric sulfate.

While it is known that certain colorless leuco bases can be oxidized to the colored dye compounds by exposure to light, and that this reaction can be accelerated by the presence of certain catalytic agents, a satisfactory photographic paper employing a triphenylmethane leuco base and a sensitizing compound of the kind above mentioned has not been, prepared heretofore. According to the present invention, any paper of suitable photographic quality can be coated on one or both sides with a solution containing the leuco base of malachite green, methyl violet, crystal violet, rosaniline and similar kind of com-. pounds, and a light-sensitive metal salt selected from the group previously mentioned. Preferably, the leuco base is first coated on the paper, the paper dried, and then the light-sensitive salt is coated from a solution over the leuco base, and the paper dried once again. The solvent for the leuco base is preferably ethyl alcohol, although other solvents such as methyl alcohol, acetone, benzene, for example, can be used, and for the metal salt the solvent most satisfactory is water.

sensitized paper prepared as above described can be exposed to light through a transparent or translucent negative, line drawing, tracing and the like. During the. exposure, the oxidation re .action initiated results in a color image whose,

depth of color varies approximately in proportion to the amount of light transmitted through relatively small, and further since bnly low con-" centrations of these materials in ordinary sol- 1 vents aren'equired, my'new photographic copying paper constitutes an economical as well as a fast reproducing material for copying line drawings, printed matter or similar contrasty subthe various parts of the pattern to. be printed.

A positive image produced from a negative ject matter, where the final permanence of the print is not a paramount consideration.

It is an object of the invention, therefore, to prepare a photographic copying paper of the kind above described. A further object is to pro-' vide a method .of preparing such-photo-sensitive paper. Another object is to provide a process for making stable prints. k I v The following examples further illustrate the preparation and application of the photographic papers of the invention.

Example] A piece of white paper was coated with a solution containing 2.5 grams of 4,4-tetramethyldiamino triphenylmethane, 0.4 gram of sodium acetate, and 0.8 gram of sodium nitrite in 250 cc. of 95% ethyl alcohol. The treated paper was dried andagain coated on the same side with a sensitizing solution consisting of approximately 1 gram of ferric chloride (FeCla-GHzO) in 100 cc. of water. After drying, the paper was covered on its coated surface with a film negative and exposed under a mercury vapor light until the 'cedure using other paper supports and other.

negatives, line drawings, translucent tracing cloths or papers.

Example 2 r I -A suitable paper was coated with a solution containing 2.5 grams of 4,4'-tetramethyldiamino triphenylmethane and 0.4 gram of sodium acetate in 250,cc. of ethyl alcohol. The treated paper was dried and then recoated on the same side with a sensitizing solution consisting of 5 grams of mercuric chloride in 100 cc. of water. After drying, the sensitized paper was placed in contact with a negative and exposed and developed as described in Example I. In this case, however, it was found that-the fixation with ammonia vapor was not nearlyjaseffective as with Example I.

In place of the 4,4-tetramethyldiamino triphenylmethane used in the above example, there can be substituted other leuco bases of the triphenylmethane series. For example, orthochloro-tetraethyldiaminotriphenylmethane sensitized with ferric chloride'an'd e p sed to light I and fixed with ammonia vapor yields 'a'satisfac-i my blue colored image. L 1

Example 3 A piece of paper was coated with a solution containing approximately 2.5 grams of 4,4'-tetramethyldiamino triphenylmethane and 1 gram of ferric chloride in 250 cc. of 95% ethyl alcohol. After drying, the sensitized paper was placed in contactwith a lined tracing paper, exposed to light and fixed with moist ammonia paper as previously described. A similar kind of product was obtained by dipping another sample of the paper into the sensitizing solution, allowing to drain, drying and fixing.

1. A photographic copying paper having on its surface a light-sensitive mixture consisting of a triphenylmethane leuco base having at least two of the phenyl nuclei substituted by amino groups in positions para to the methane carbon atom, and a sensitizing salt selected from the group consisting of ferric chloride, mercuric chloride, mercuric acetate, stannic chloride, zinc chloride, and cupric sulfate;

2. A photographic copying paper having on its surface a light-sensitive mixture consisting of a triphenylmethane leuco base having at least two of the phenyl nuclei substituted by amino groups in positions para to the methane carbon atom, and ferric chloride as a sensitizing salt.

3. A photographic copying paper having on its surface a. light-sensitive mixture consisting of a triphenylmethane leuco base having at least two of the phenyl nuclei substituted by amino groups in positions para to the methane carbon atom, and mercuric-chloride as a sensitizing salt.

4. A photographic copying paper having on its surface a light-sensitive mixture consisting of leucomalachite green, and a sensitizing salt se-- lected from the group consisting of ferric chloride, mercuric chloride, mercuric acetate, stannic chloride, zinc chloride, and cupric sulfate.

A photographic copying paper having on its surface a light-sensitive mixture consisting of leucomalachite green, and ferric chloride as a sensitizing salt. v

6. A photographic copying paper having on its Surface a light sensitive mixture consisting of leucomalachite green and mercuric chloride as a sensitizing salt.

'7. A process for making photographic prints comprising the steps of coating 9. paper with asolution comprising a. triphenylmethane leuco base having at least two of the phenyl nuclei substituted by amino groups in positions para to the methane carbon atom, drying the paper, recoating the coated surface of the paper with a solution comprising a sensitizing salt selected from the group consisting of ferric chloride, mercuric chloride, mercuric acetate, stanmc chloride, zinc chloride, and cupric sulfate, redrying the paper, exposing the sensitized and dried paper to light under a transparent pattern, and fixing the print with moist ammonia vapor.

8. A process for making photographic prints comprising the steps of coating a paper with a solution comprising a triphenylmethane leuco base having at least two of the phenyl nuclei substituted by amino groups in positions para to the methane carbon atom, drying the paper, recoating the coated surface of the paper with a solution comprising ferric chloride as the'sensitizing salt, redrying the paper, exposing the sensitized and dried paper to light under a transparent pattern, and fixing the print with moist ammonia vapor.

comprising the steps of coating a. paper with a solution comprising a triphenylmethane leuco base having at least two of the phenyl nuclei substituted by amino groups in positions para to the methane carbon atom, drying the paper, recoating the coated surface of the paper with a solution comprising mercuric chloride as the sensitizing salt, redrying the paper, exposing the sensitized and dried paper to light under a transparent pattern, and fixing the print with moist ammonia vapor.

10. A process for making photographic prints comprising the steps ofcoating a paper with a solution comprising leucomalachite green, drying the paper, recoating the coated surface of the paper with a solution comprising a sensitizing salt selected from the group consisting of ferric chloride, mercuric chloride, mercuric acetate, stannic chloride, zinc chloride, and cupric sulfate, redrying the paper, exposing the sensitized and dried paper to light under a transparent pattern, and fixing the print with moist ammonia vapor.

11. A process for making photographic prints comprising the steps of coating a paper with a solution comprising a leucomalachite green, ingthe paper, recoating the coated surface of the paper with a solution comprising ferricchloride as the sensitizing salt, redrying the paper, exposing the sensitized and dried paper to light under a transparent pattern, and fixing the print with moist ammonia vapor.

12. A process for making photographic prints comprising the steps of coating a paper with a solution comprising a leucomalachite green, ying the paper, recoati'ng the coated surface of the paper with a solution comprising mercuric chloride as the sensitizing salt, redrying the paper, exposing the sensitized and dried paper to light under a transparent pattern, and fixing the print with moist ammonia vapor.

' 13. A process for making photographic prints comprising the steps or coating a paper with a solution comprising a triphenylmethane leuco base having at least two of the phenyl nuclei substituted by amino groups in positions para to the methane carbon atom and a sensitizing salt selected from the group consisting of ferric chloride, mercuric chloride, mercuric acetate, stannic 0 chloride, zinc chloride, and cupric sulfate, drying 5 comprising thesteps of coating a paper with a 9. A process for making photographic prints solution comprising a triphenylmethane leuco 'base having at least two of the phenyl-nuclei substituted by amino groups in positions para to the methane carbon atom and ferric chloride as the sensitizing salt, drying the paper, exposing the sensitized and dried paper to light under a transparent pattern, and fixing the print with moist ammonia vapor.

15. A process for making photographic prints comprising the steps of coating a paper with a solution comprising a; triphenylmethane leuco base having at least two of the phenyl nuclei substituted by amino groups in positions para to the methane carbon atom and mecuric chloride as the sensitizing salt, drying the paper, exposing the sensitized and dried paper to light under a transparent pattern, and fixing the print with moist ammonia vapor.

- FRED W. BOUGH'IDN. 

